1. Field of the Invention
The present invention relates in general to a reinforced, flexible plastic hose construction, and method for making same, suitable for use in cleaning swimming pools, air vacuum systems, and other duct applications. More specifically, it relates to a flexible hose having contiguous turns of an extruded plastic strip that are sealed and bonded together by an extruded helical bead.
2. Description of the Prior Art
Vacuum apparatus used for drawing liquid and foreign particles through the apparatus (i.e., maintenance of swimming pools), or for very low air pressure systems, require a strong, non-collapsible, yet flexible hose that is light in weight.
Conventional hoses provide a degree of flexibility and are constructed of metal or plastic material. The metal hose normally is a strip of metal wound into a helix and is covered with a plastic sheet material. These metal hoses provide a number of disadvantages. The hose is heavy for application to certain uses (i.e., cleaning swimming pools). The hose will sink to the bottom of the pool and is extremely difficult to position for proper use. Furthermore, the flexibility or elasticity is restricted since the metal may not readily return to its original shape after being bent and the tensile strength of the hose may be weak due to poor bonding of adjacent metal turns.
Plastic hoses are both lighter and more flexible. Conventional plastic hoses have an interlocking arrangement wherein each turn overlays and mates with the adjacent turn forming a rib. A hot seal of plastic material may be added between overlays of adjacent turns and a separate extruded strip of plastic may be used to cap the rib.
U.S. Pat. No. 3,255,780, discloses a conventional helically wound and helically ribbed plastic hose of the foregoing general nature. A hook-shaped portion on a first side of a plastic strip engages a leg member on a second side of the plastic strip, the leg member being from the preceeding helical, or adjacent, turn. A hot seal is inserted between the leg member and the hook-shaped portion. U.S. Pat. No. 2,731,040, discloses an interlocking arrangement without a bead and U.S. Pat. No. 3,273,600, discloses the use of a separate strip as a cap which is sealed to the leg member by a hot seal.
A disadvantage of this interlocking arrangement is that it creates additional bulk in the rib reducing flexibility. Also the additional cap of plastic adds more bulk and increases both the weight and cost of the hose.
Accordingly, it is an object of the invention to provide a new hose and method for making a hose which is light in weight, flexible, less costly to manufacture and which has thin, flexible ribs providing increased strength.
Another object is to provide a rib construction with a more readibly inspectable design over the prior art.